A study was carried out and subjects were randomized to 2 groups:
Group A: control diet group, N=154
Group B: a fruit-and-vegetable group, N=154.
The 97.5% CI for mean changes in Group B minus mean change in Group A is (-4.7 to -0.9). Suppose we want to compute a two-sided p-value to compare the two groups. Without doing

1. What are the four levels of measurement scales? Give examples of each and explain in detail.
2. Explain the use of normal probability plot to evaluate whether a set of data is normally distributed? Please discuss in detail.
3. Discuss how a sample size, n, an increase in confidence is achieved by widening the confidenc

A college class believes that the average grade average of psychology students and the average grade averages of biology students are different. The class found that the actual grade averages of a sample of 8 psychology students was 3.5 and the average grade average of a sample of 11 biology students was 3.2. What is the null hy

See attached file.
Measuring Differences Between Two Means
Over the past year, the Vice President of Human Resources at a large medical center has run a series of three-month workshops aimed at increasing worker motivation and performance. To check the effectiveness of the workshops, she selected a random sample of 35 emp

Question #1- Using your experience from previous or current employment, provide a business example where you could use a t-test to assist in a business decision. State the null and alternative hypothesis. The null and alternative should be the exact opposite of each other and the t-test will be looking for a difference between t

Using AIU's survey responses from the AIU data set, complete the following requirements in the form of a report:
Perform a two-tailed hypothesis test on the intrinsic variable AND a two-tailed hypothesis test on the extrinsic variable's data using a .05 significance level.
Begin by creating a null and an alternate statement.

Are the following statements
Ho: mu "greater than or equal to" 11
Ha: mu "greater than or equal to" 18
a valid pair of null and alternative hypothesis?
A) No, there are no parameters contained in these statements
B) No, the alternative hypothesis cannot contain numeric values
C) No, these statements have overlap

Set up and solve each of the following problems using the Excel files. Be prepared to answer questions regarding the direction of the hypothesis test, the p-value, the decision to reject or not, and the conclusion.
1. ONE SAMPLE HYPOTHESIS TEST FOR MEAN: A bowler who has averaged 196 pins in the past year is asked to exper

Imagine that you have been contracted to create a test to assist in the admission process at a university. What factors would be considered and what steps would be taken to ensure reliability and validity of this test? Explain why these factors and steps are important.

A summary on the daily consumption of caffeine for a sample size of 49 adult women produced:
Ð? = 49
X bar = 215 mg
s = 235 mg
range: 5 to 1176
1. Does it appear plausible that the population distribution of daily caffeine consumption is normal? Explain
2. Is it necessary to assume a normal population distribut

A mayoral election race is tightly contested. In a random sample of 1,100 likely voters, 572 said they were planning to vote for the current mayor. Based on this sample, what is your initial hunch? Would you claim with 95% confidence that the mayor will win a majority of the votes? Explain.

See attached file.
Measuring Differences Among Three or More Means
Modern software applications require rapid data access capabilities. An experiment was conducted to test the effect of data file size on the ability to access the files (as measured by read time, in milliseconds). Three different levels of data file size w

See attached data file.
Assignment 6
Measuring Differences Between Two Means (1)
Go to the Resources section in this syllabus and open the file restaurants.xls. This data file contains ratings for food, decor, service, and the price per person for a sample of 50 restaurants located in an urban area and 50 restaurants

Data from the motor vehicle department indicate that 80% of all licensed drivers are older than age 25.
a) In a sample of n= 60 people who recently received speeding tickets, 38 were older than 25 years and the other 22 were age 25 or younger. Is the age distribution for this sample significantly different from the distributi

Human Body Temperature: What's Normal?
In an article in the Journal of Statistics Education (vol. 4, no. 2, 1996), Allen Shoemaker describes a study that was reported in the Journal of the American Medical Association.* It is generally accepted that the mean body temperature of adult humans is 98.6°F. In his article, Shoemaker

Problems 23 & 37
For each claim, assume the distribution of the population is approximately normal.
23. Microwave Repair Costs &#9670; A microwave oven repairer says that the mean repair cost for damaged microwave ovens is less than $100.You work for the repairer and want to test this claim. You find that a random sample

If a random sample of 10 people found that 9 were pro-life (i.e., 90%), while another random sample of 1000 people from the same population found that 550 were pro-life (i.e., 55%), which would you find more significant? Why?
Offer any personal experiences where you might have trusted results from a small sample more than t

An engineering firm is evaluating their back charges. They originally believed their average back charge was $1800. They are concerned that the true average is higher, which could hurt their quarterly earnings. They randomly select 40 customers, and calculate the corresponding sample mean back charge to be $1950. If the standa

Prepare an analysis of your selected article. Start by identifying and summarizing the hypothesis described in the article. Then explain whether the hypothesis was rejected or accepted, and what the implications of this finding are for the study.
Use the following article: Job satisfaction of managers in tourism: Cases in the

The structure of a two-factor study can be presented as matrix with the levels of one factor determining the rows and the levels of the second factor determining the columns. With this structure in mind, describe the mean differences that are evaluated by each of the three hypothesis tests that make up a two-factor ANOVA.

1. Given the linear correlation coefficient r and the sample size n, determine the critical values of r and use your finding to state whether or not the given r represents a significant linear correlation. Use a significance level of .05.
R = -0.8444, n=5
Critical values: r =± 0.950, no significant linear correlation

(TCO 8) The mean age of school bus drivers in Denver is claimed to be 56.9 years. A hypothesis test is performed at a level of significance of 0.05 with a P-value of 0.03. Choose the best interpretation of the hypothesis test.
Reject the null hypothesis; there is enough evidence to reject the claim that the mean ag

(TCO 11) A 15-minute Oil and Lube service claims that their average service time is no more than 15 minutes. A random sample of 40 service times was collected, and the sample mean was found to be 15.4 minutes, with a sample standard deviation of 3.2 minutes. Is there evidence to support, or to reject the claim at the alpha = 0.0

Please show all work.
More men than women were randomly assigned to the Clardozan group. After a careful examination of the results, the pharmaceutical company wonders if gender influenced the results. Conduct a test to determine if there was a relationship between gender and group assignment using the .05 level of signific

Problem A
The manager of a grocery store claims that the average time that customers spend in checkout lines is 20 minutes or less. A sample of 36 customers is taken. The average time spent on checkout lines for the sample is 24.6 minutes; and the sample standard deviation is 12 minutes. Conduct a hypothesis test (at 0.05 l

1. Last year, according to consumer group, the average passenger vehicle was driven 10.3 thousand miles with a standard deviation of 2 thousand miles before a claim of accident was made. A random sample of 225 passenger cars was collected by the auto insurance company which showed a mean of 10.1 thousand miles driven when a cl

Suppose a wedding photographer claims he can finish a bride's wedding photos in less than 7 days. You are given the following data from a sample.
Sample size: 40
Population standard deviation: 1
Sample mean: 7.2
Formulate a hypothesis test to evaluate the claim. Which one is correct?
A) Ho: µ = 7; Ha:

A PC manufacturer claims that no more than 5% of their machines are defective. In a random sample of 100 machines, it is found that 8.5% are defective. The manufacturer claims this is a fluke of the sample. At a .02 level of significance, test the manufacture's claim, and explain your answer..
MegaStat Output
Hypothesis tes